匹配兩行，替換為三行

Question

我需要使用sed將每個匹配的兩線模式替換為三線模式。 這是我的輸入文件（ tempfile.txt ）。

lease 192.168.6.100 {
  binding state free;
  hardware ethernet 00:e0:4c:68:00:96;
}
lease 192.168.6.100 {
  binding state active;
  hardware ethernet 00:e0:4c:68:00:96;
  client-hostname "andrew-H81M-S2PH";
}
lease 192.168.6.100 {
  binding state free;
  hardware ethernet 00:e0:4c:68:00:96;
}
lease 192.168.6.100 {
  binding state active;
  hardware ethernet 00:e0:4c:68:00:96;
  client-hostname "andrew-H81M-S2PH";
}

基本上，如果client-hostname "HOSTNAME"; 缺少，則應先使用tab ，然后再使用newline替換它。

我的嘗試： sed 'N; /hardware.*}/d; P; D' tempfile.txt sed 'N; /hardware.*}/d; P; D' tempfile.txt

結果是：

lease 192.168.6.100 {
  binding state free;
lease 192.168.6.100 {
  binding state active;
  hardware ethernet 00:e0:4c:68:00:96;
  client-hostname "andrew-H81M-S2PH";
}
lease 192.168.6.100 {
  binding state free;
lease 192.168.6.100 {
  binding state active;
  hardware ethernet 00:e0:4c:68:00:96;
  client-hostname "andrew-H81M-S2PH";
}

這是我想要的輸出。

lease 192.168.6.100 {
  binding state free;
  hardware ethernet 00:e0:4c:68:00:96;
  <tab>
}
lease 192.168.6.100 {
  binding state active;
  hardware ethernet 00:e0:4c:68:00:96;
  client-hostname "andrew-H81M-S2PH";
}
lease 192.168.6.100 {
  binding state free;
  hardware ethernet 00:e0:4c:68:00:96;
  <tab>
}
lease 192.168.6.100 {
  binding state active;
  hardware ethernet 00:e0:4c:68:00:96;
  client-hostname "andrew-H81M-S2PH";
}

正如您所看到的，在小卷發之間始終有三條線。 這就是我的目標。

Answer 1

這可以解決問題（將管道打到cat -A以顯示不可打印的字符）：

$ sed -r 'N;s/^([[:space:]]*hardware.*)(\n})$/\1\n\t\2/;t;P;D' infile | cat -A
lease 192.168.6.100 {$
  binding state free;$
  hardware ethernet 00:e0:4c:68:00:96;$
^I$
}$
lease 192.168.6.100 {$
  binding state active;$
  hardware ethernet 00:e0:4c:68:00:96;$
  client-hostname "andrew-H81M-S2PH";$
}$
lease 192.168.6.100 {$
  binding state free;$
  hardware ethernet 00:e0:4c:68:00:96;$
^I$
}$
lease 192.168.6.100 {$
  binding state active;$
  hardware ethernet 00:e0:4c:68:00:96;$
  client-hostname "andrew-H81M-S2PH";$
}$

而不是刪除匹配項，而是捕獲應該包圍空行的兩行，並用換行符和之間的制表符代替。 我還添加了一些錨點以實現更安全的匹配。

涉及一些技巧，因為模式空間在替換后包含兩個換行符，但是P;D僅打印第一行並開始一個新循環，這也會在包含client-hostname行之后導致不需要的換行符。

詳細解釋：

N       # Append next line to pattern space

# If the hostname is missing, insert a newline and a tab
s/^([[:space:]]*hardware.*)(\n})$/\1\n\t\2/

t      # If we did the substitution, jump to end (prints complete pattern space)
P      # Print first line in pattern space
D      # Delete first line in pattern space - starts new cycle

Answer 2

我冒昧地增加了另一個卷曲...

sed 'N; s/hardware.*}/\t\n}/; P; D' andy
lease 192.168.6.100 {
  binding state free;

}
lease 192.168.6.100 {
  binding state active;
  hardware ethernet 00:e0:4c:68:00:96;
  client-hostname "andrew-H81M-S2PH";
}
lease 192.168.6.100 {
  binding state free;

}
lease 192.168.6.100 {
  binding state active;
  hardware ethernet 00:e0:4c:68:00:96;
  client-hostname "andrew-H81M-S2PH";
}